Use of host population reduction to control wildlife infection: rabbits and paratuberculosis.

Reduction in wildlife populations is a common method for the control of livestock infections which have wildlife hosts, but its success is dependent on the characteristics of the infection itself, as well as on the spatial and social structure of the wildlife host. Paratuberculosis (Mycobacterium avium subsp. paratuberculosis; Map) is a widespread and difficult infection to control in livestock populations and also has possible links to Crohn's disease in humans. Rabbits have recently been identified as a key wildlife species in terms of paratuberculosis persistence in the environment and risk to the wider host community, including cattle. Here we use a spatially explicit stochastic simulation model of Map dynamics in rabbit populations to quantify the effects of rabbit population control on infection persistence. The model parameters were estimated from empirical studies of rabbit population dynamics and rabbit-to-rabbit routes of Map transmission. Three rabbit control strategies were compared: single unrepeated population reductions based on removing individual animals; single unrepeated population reductions based on removal of entire social groups; and repeated annual population reductions based on removing individual animals. Unrealistically high rabbit culls (>95% population reduction) are needed if infection is to be eradicated from local rabbit populations with a single one-off population reduction event, either of individuals or social groups. Repeated annual culls are more effective at reducing the prevalence of infection in rabbit populations and eradicating infection. However, annual population reductions of >40% are required over extended periods of time (many years). Thus, using an approach which is both highly conservative and parsimonious with respect to estimating lower bounds on the time to eradicate the infection, we find that Map is extremely persistent in rabbit populations and requires significant and prolonged effort to achieve control.

Displaced fractures of the hip in children. Management by early operation and immobilisation in a hip spica cast.

Fractures of the hip in children have been associated with a very high rate of serious complications including avascular necrosis (up to 47%) and coxa vara (up to 32%). Over a period of 20 years, we have treated displaced fractures by early anatomical reduction, internal fixation and immobilisation in a spica cast to try to reduce these complications. We have reviewed 18 patients who had a displaced non-pathological fracture of the hip when under 16 years of age. Their mean age at the time of the injury was eight years (2 to 13). They returned for examination and radiography at a mean follow-up of eight years (2 to 17). Each patient had been treated by early (" 24 hours) closed or open reduction with internal fixation and 16 had immobilisation in a spica cast. By Delbet's classification, there was one type-I, eight type-II, eight type-III, and one type-IV fractures. There were no complications in 15 patients. Avascular necrosis occurred in one patient (type-III), nonunion in one (type-II, one of the two patients who did not have a cast) and premature physeal closure in one (type-I). There were no cases of infection or complications as a result of the cast. Our treatment of displaced hip fractures in children by early reduction, internal fixation, and immobilisation in a spica cast gave reduced rates of complications compared with that of large published series in the literature.

Metatarsal lengthening.

Metatarsal lengthening for brachymetatarsia is a good procedure that can improve appearance and function. There are risks to these procedures, which should be understood thoroughly.

The surgical management of pulmonary metastasis: current concepts.

Lung metastases have been found in 25-30% of all patients with cancer at autopsy. Those patients satisfying criteria for surgical resection represent a much smaller subgroup. Given the potentially curative nature of pulmonary metastasectomy in the absence of disseminated disease, it has become widely accepted as an important treatment option for a variety of malignancies with metastasis to the lungs. A standardized approach remains unfounded however, given limited numbers of patients, various histologic subtypes and few published studies utilizing randomized prospective methodology.Ultimately, the development of metastasis represents a major determinant of survival for patients with cancer. Pulmonary metastasectomy is an important treatment modality for patients with metastatic pulmonary disease. The indications for pulmonary metastasectomy and the surgeon's role in pulmonary metastatic disease continue to evolve. Future prospective studies and the compilation of comparable data yielding prognostic factors for specific histologies will better define indications for resection.

Angle-closure glaucoma in association with orbital pseudotumor.

PURPOSE: To describe the pathophysiology of angle-closure glaucoma secondary to idiopathic inflammatory orbital pseudotumor. DESIGN: Retrospective, small noncomparative case series. PARTICIPANTS: Three patients with angle-closure glaucoma and orbital pseudotumor. METHODS: The pathophysiology of this entity was investigated using magnetic resonant imaging (MRI) and ultrasound biomicroscopy (UBM). MAIN OUTCOMES MEASURES: Clinical features, anterior chamber angle configuration, and intraocular pressure. RESULTS: Angle closure from anterior rotation of the ciliary body caused by choroidal effusions secondary to pseudotumor was demonstrated using MRI and UBM. Two of the three cases resolved after treatment for orbital pseudotumor. CONCLUSIONS: Idiopathic orbital pseudotumor is a cause of secondary angle-closure glaucoma. The mechanism of angle closure is anterior rotation of the ciliary body secondary to choroidal effusions resulting from the orbital inflammation.

Early radiographic differentiation of infantile tibia vara from physiologic bowing using the femoral-tibial ratio.

SUMMARY: The authors hypothesized that the ratio of the femoral to tibial metaphyseal-diaphyseal angles (femoral-tibial ratio [FTR]) more accurately differentiates physiologic bowing from infantile tibial vara than the tibial metaphyseal-diaphyseal angle (TMDA). The purpose of this study was threefold: to determine the false-negative and false-positive error rate of the FTR and TMDA; to determine to the effect of rotation on the FTR and TMDA; and to determine the reliability of the FTR and TMDA measurements. An FTR < 1 resulted in a false-negative error rate of 10% and a false-positive error rate of 7%, whereas a TMDA > 13 degrees resulted in a false-negative error rate of 23% and a false-positive error rate of 10%. The difference between internal and external rotation was not significant for the FTR, whereas it was for the TMDA. The FTR was found to have good interobserver and intraobserver reliability (0.78 and 0.98, respectively).

When does the flat-top talus lesion occur in idiopathic clubfoot: evaluation with magnetic resonance imaging at three months of age.

Flat-top talus has been described as a pathologic change secondary to idiopathic clubfoot condition and/or as a direct result of nonoperative manipulation involving forced dorsiflexion and molding of the cartilaginous talus. No definitive study, however, on the etiology and the timing of the flat-top talus deformity has been performed to date. The authors evaluated the magnetic resonance images of eleven patients with idiopathic clubfoot deformities treated with 2 to 3 months of casting to assess if flattening of the talar dome occurred at this age with this amount of casting. All children were 3 months of age, were casted for a maximum of 2 to 3 months, and sedated before MRI examination. The images were evaluated for maximum talar head height, maximum talar body height, and deviation of the talar body from a perfect circle. Maximum talar head height ranged from 4 to 9 mm, maximum talar body height ranged from 6 to 10 mm. Eight of the eleven had maximum talar body measurements 3 to 5mm greater than maximum talar head height. Three of the eleven patients had head and body size of equal proportion. Two of the eleven had a talar body that was within 1 mm of a perfect circle. The remaining nine patients had perfectly round talar bodies. In the senior author's (RSD) experience with treating clubfeet, a substantial increase has been seen at operation in flat-top tali among children that were casted for more than 1 year before surgical correction, compared to children casted for 3 months before surgical correction. The current investigation indicated that although tali of children with clubfeet are abnormally shaped, the talar body remains larger than the talar head and maintains its roundness after two to three months of corrective casting. Maintenance of cast treatment for more than three months may lead to the flat-top talus deformity. The authors recommend surgical intervention following three months of failed manipulation and casting to prevent this deformity.

Talo-navicular arthrodesis for residual midfoot deformities of a previously corrected clubfoot.

Triangular navicular, dorsal-lateral subluxation of the talo-navicular (TN) joint with a secondary forefoot cavovarus deformity, and degenerative changes of the TN joint are frequent causes of residual clubfoot deformity and pain in the midfoot after surgical correction. This study investigates the usefulness of TN arthrodesis to correct these deformities and to resolve symptoms resulting from these deformities. During the period from 1991-1996, the senior author performed 19 TN fusions (16 patients) for the above residual clubfoot deformities involving a painful TN joint. Eight of the procedures (seven patients) also required a lateral column shortening with a calcaneal wedge osteotomy to allow for a complete correction of the TN joint. The procedure was only performed in cases involving a hindfoot that was adequately aligned during a previous clubfoot correction. The average age of the patients at the time of surgery was 11 years (range: 4-20). One patient (bilateral procedures) was lost to follow-up. Fifteen patients (17 procedures) were followed-up for an average of four years (range: 2-6). All patients reported symptomatic improvement after the TN arthrodesis. Fourteen of the patients (15 procedures) were completely satisfied. The remaining patient (bilateral procedures) was only partially satisfied due to the subsequent development of navicular-cuneiform osteoarthritis in both feet. Two cases (2 patients) developed complications requiring a second procedure for satisfactory results. In addition, the procedure resulted in an improvement of the talus-first metatarsal angle on both antero-posterior and lateral radiographs. TN arthrodesis produced a correction of the residual clubfoot deformities of the midfoot and resulted in satisfactory clinical improvement in all the patients.

Growth disturbances after distal tibial physeal fractures.

Twenty-four patients with distal tibial growth disturbance were reviewed. Disturbances were classified as physeal bar (prior to deformity), angular, linear or combined deformities. Treatment consisted of osteotomy in fourteen, epiphyseodesis in seven, excision of bony bar in two, and observation in one patient. Follow up was an average 36.6 months (range 4-129 months) after treatment of growth disturbance. The age at time of injury was 10.4 years of age average (range 3-15 years). There were 12 SH2, 2 SH3, 7 SH4, and 3 SH5 distal tibial physeal fractures. Thirteen of 15 fractures considered high energy and only 1 of 9 fractures considered low energy resulted in angular deformity. Angular and linear deformities presented an average 46 months (range 12-120 months) and physeal bars at an average 14 months (range 6-25 months) after injury. Patients with a delay in presentation of growth disturbance greater than 24 months had angular deformities in 92% compared with 33% in children presenting less than or at 24 months. Treatment based on type of deformity, age at time of injury, and growth remaining was considered successful in 83%. Patients with angular or linear deformities were more likely to present late, have high energy injuries, be male patients and have Salter-Harris types IV and V. Early diagnosis and treatment of growth disturbance can prevent severe deformity.

Fibrous lesion of the distal femur associated with angular deformity.

Unilateral femoral angulation is uncommon. We describe two children with unilateral progressive distal femoral varus and limb-length discrepancy. These deformities were associated with a fibrous lesion involving the medial aspect of the distal femoral metaphysis. Both patients were 15 to 16 months old. In both, the deformity was progressive, resulting in excisional biopsy and osteotomy. The gross and microscopic appearance of both lesions was similar, and the histology was dense fibrous connective tissue. The patients' femoral alignment was maintained at follow-up of a minimum of 16-36 months. The etiology of these lesions is unknown; they are associated with progressive deformity and appear to respond well to surgical intervention.

Surgical management of calcaneal unicameral bone cysts.

Unicameral bone cysts are not seen commonly in the calcaneus. Little is known about the etiology and natural history of these lesions. Calcaneal cysts often are symptomatic, although some of these lesions are detected as incidental findings. Treatment has been advocated based on the fear of pathologic fracture and collapse. Several published series have been divided in their favor for either open treatment or injection management. These series are small, and the optimal treatment is still in question. The current study compared the efficacy of methylprednisolone acetate injection treatment with curettage and bone grafting in the treatment of unicameral bone cysts of the calcaneus. All patients treated for unicameral bone cysts of the calcaneus during the past 7 years at two institutions were reviewed. Eleven patients met inclusion criteria. All diagnoses were confirmed radiographically or histologically. Demographic information, presenting complaints, diagnostic imaging, treatment modalities, and outcome were analyzed. Long term radiographic and subjective followup was obtained. Eighteen surgical procedures were performed on 11 patients with 12 cysts. Nine injections performed on six patients failed to show healing of the cyst. Nine cysts treated with curettage and bone grafting showed cyst healing. At mean followup of 28 months (range, 12-77 months), all 11 patients had no symptoms; there were no recurrences of the cyst in the nine patients who underwent bone grafting and persistence of the cyst in the two patients who underwent injection therapy. This review reports one of the largest series of cysts in this location. The results indicate that steroid injection treatment, although useful in other locations, may not be the best option for the management of unicameral bone cysts in the calcaneus. Curettage and bone grafting yielded uniformly good results.

Pretreatment bone scan in SCFE: a predictor of ischemia and avascular necrosis.

Sixty-two consecutive patients with 73 slipped capital femoral epiphyses (SCFEs) underwent pretreatment planar technetium bone scan to identify the presence of ischemia of the femoral head. The relationship of pretreatment ischemia and the development of avascular necrosis (AVN) was evaluated after a minimum follow-up of 12 months. All patients were treated with spica casting or pinning across the physis. No forceful manipulation was performed. None of the 63 stable SCFEs demonstrated ischemia by bone scan, and none developed AVN. Of the 10 unstable SCFEs, six demonstrated ischemia by bone scan, and five of the six developed AVN. None of the four unstable SCFEs without ischemia on bone scan developed AVN. Pretreatment bone scan is a sensitive predictor for development of AVN in unstable SCFEs and may provide a method for evaluating interventional treatments for AVN associated with SCFE.

Diagnosing aneurysmal and unicameral bone cysts with magnetic resonance imaging.

The differential between aneurysmal bone cysts and unicameral bone cysts usually is clear clinically and radiographically. Occasionally there are cases in which the diagnosis is not clear. Because natural history and treatment are different, the ability to distinguish between these two entities before surgery is important. The authors reviewed, in a blinded fashion, the preoperative magnetic resonance images to investigate criteria that could be used to differentiate between the two lesions. All patients had operative or pathologic confirmation of an aneurysmal bone cyst or unicameral bone cyst. The authors analyzed the preoperative magnetic resonance images of 14 patients with diagnostically difficult bone cysts (eight children with unicameral bone cysts and six children with aneurysmal bone cysts) and correlated these findings with diagnosis after biopsy or cyst aspiration and contrast injection. The presence of a double density fluid level within the lesion strongly indicated that the lesion was an aneurysmal bone cyst, rather than a unicameral bone cyst. Other criteria that suggested the lesion was an aneurysmal bone cyst were the presence of septations within the lesion and signal characteristics of low intensity on T1 images and high intensity on T2 images. The authors identified a way of helping to differentiate between aneurysmal bone cysts and unicameral bone cysts on magnetic resonance images. Double density fluid level, septation, and low signal on T1 images and high signal on T2 images strongly suggest the bone cyst in question is an aneurysmal bone cyst, rather than a unicameral bone cyst. This may be helpful before surgery for the child who has a cystic lesion for which radiographic features do not allow a clear differentiation of unicameral bone cyst from aneurysmal bone cyst.

Orthopaedic manifestations of chronic graft-versus-host disease.

Chronic graft-versus-host disease (GVHD) is a well-recognized complication of allogeneic bone marrow transplantation (BMT). Musculoskeletal manifestations include joint contractures, polymyositis, polyserositis, and fasciitis. We present 14 patients with orthopaedic complications of chronic GVHD. Long-term conservative management of joint contractures with physical therapy and orthotics was generally successful in restoring patients' premorbid functional status. Surgical release of joint contractures yielded poor results and rendered the affected joints unresponsive to further conservative treatment. Surgical intervention in the treatment of joint contractures resulting from chronic GVHD does not appear qualitatively to improve functional status in patients affected with this disease process.

Neoadjuvant chemoradiotherapy for esophageal cancer: is it worthwhile?

BACKGROUND: With promising results from several institutions, many centers began treating patients with esophageal cancer with neoadjuvant chemoradiotherapy (NC) followed by esophagectomy. This approach is demanding for the patient and has not been proved to be better than esophagectomy alone. OBJECTIVE: To assess survival time and measures of quality of life associated with NC. DESIGN: A retrospective review during 1990 to 1996. SETTING: The 3 tertiary academic hospitals affiliated with the University of Massachusetts Medical School, Worcester. PARTICIPANTS: All patients (N=51) with cancer of the middle or lower esophagus who were treated with NC followed by esophagectomy during this period. MAIN OUTCOME MEASURES: Median and 1-, 2-, and 3-year survival times; median preoperative treatment time (first office visit for surgical consultation before beginning NC to the date of surgery), median hospital stay, and postoperative swallowing function. RESULTS: The median survival time of all patients was 16.3 months; 1-, 2-, and 3-year overall survival rates were 67%, 46%, and 39%, respectively. The median hospital stay was 12 days. The median postoperative treatment time was 3.3 months, which was 20% of the median survival time. Of the 51 patients, 19 were alive with a median follow-up time of 2.5 years. Twenty-nine percent of the patients had a complete pathological response with median and 1-, 2-, and 3-year survival rates of 17.5 months, 73%, 57%, and 57%, respectively. Palliation of dysphagia was excellent, with 44 (93%) of 47 operative survivors taking either a soft diet (18 [38%]) or a regular (26 [55%]) diet by the first postoperative visit. CONCLUSIONS: Median survival time with NC followed by esophagectomy for resectable cancer of the esophagus does not appear to be significantly better than that reported for esophagectomy alone. Further, treatment time with NC consumed 20% of survival time. Examining only these outcome variables suggests that NC is not worth-while. However, examining a longer-term outcome survival variable, such as 3-year survival time, suggests that NC followed by esophagectomy may result in greater long-term survival than that reported for esophagectomy alone. We conclude that further randomized, controlled studies are necessary before NC followed by esophagectomy is considered superior to esophagectomy alone for the treatment of resectable esophageal cancer.

Pediatric fracture without radiographic abnormality. Description and significance.

With an expanding application of magnetic resonance imaging in acute musculoskeletal injury, an increasing number of occult traumatic lesions of bone are being identified. The authors describe the entity of fracture without radiographic abnormality, which as the name suggests is a bony injury not apparent on plain radiographs. The clinical significance and potential sequelae have not been defined in the pediatric patient. Accordingly, the purpose of this study is to describe and classify the entity of the pediatric fracture without radiographic abnormality and delineate its importance and appropriate management. Twenty-five children were seen primarily or referred to The Children's Hospital of Philadelphia after having sustained an acute traumatic injury; all refused to bear weight or use their extremity, and all had initial plain radiographs that were interpreted as normal. Subsequent magnetic resonance images of all 25 children showed an occult fracture. These included Salter-Harris fracture Types II (two patients), III (one patient), and IV (three patients), intraosseous epiphyseal fractures (18 patients), and a metaphyseal diaphyseal fracture (one patient). Four patients with intraosseous epiphyseal fractures ultimately sloughed a portion of their articular cartilage, as observed at arthroscopy. The decision to proceed with magnetic resonance imaging in the evaluation of a child who refuses to use an extremity depends on many variables. However, magnetic resonance imaging has proven useful in revealing fractures without radiographic abnormality and in ruling out other pathosis.

Accessory soleus muscle. A report of 4 cases and review of literature.

Cadaveric studies have demonstrated the incidence of an accessory soleus muscle ranges from 0.7% to 5.5%. The differential diagnosis of a painful soft tissue mass in the posteromedial region of the ankle includes ganglion, lipoma, hemangioma, synovioma, and sarcomas. In light of these possibilities, most of the early reports of accessory soleus included evaluation and treatment with biopsy, fasciotomy, or excision. Four patients, ranging in age from 14 to 66 years of age at the time of presentation, are discussed. Reports in the literature indicate that accessory soleus is a benign condition, and in most patients, a conservative approach is indicated. In addition, magnetic resonance imaging is the preferred study for the evaluation of this condition. If a diagnosis of accessory soleus is made, and the patient has no symptoms, observation is recommended. However, if the patient has symptoms, fasciotomy generally is a successful form of treatment. For symptoms that persist after fasciotomy, excision of the accessory soleus can be curative.

Scoliosis in patients treated with growth hormone.

Two hundred fifty children being treated with growth hormone were screened for scoliosis by using the Adams and Bunnell techniques. If indicated, an anteroposterior radiograph was done and measured by the Cobb and Risser methods. Scoliosis was defined as a frontal curve of > or = 10 degrees; progression, as a sustained increase of > or = 5 degrees, and a progressive curve as one > or = 25 degrees and meeting our criteria for orthotic management. In 10 of the 250 patients, scoliosis developed. Six curves were double major thoracic and lumbar; three thoraco-lumbar; and one single thoracic. Six of the 10 patients had progressive curves and required an orthosis. Their average annualized rate of progression was 26 degrees. Progression was associated with double major curves and an earlier Risser stage. Despite bracing, progression continued to fusion in three patients. We conclude that growth hormone may increase the risk of progression of scoliosis. Furthermore, the progression is frequently rapid and requires special vigilance by the treating physician.

Bone infarction versus infection in sickle cell disease in children.

We reviewed emergency admissions for the complaint of musculoskeletal symptoms for 113 children with sickle cell disease. Over a 2-year period, we accumulated a total of 247 admissions to a major children's hospital. Four osteoarticular infections were identified, resulting in an incidence of 1.6% per admission for musculoskeletal complaints. Admission history, physical findings, laboratory values, and radiographic studies were reviewed. We compared findings in the group with the positive diagnosis of osteoarticular infections with those who were thought to have only vaso-occlusive crisis. Although three of the four patients with infection had plain roentgenogram changes at the time of diagnosis, no statistically significant differences in the two groups could be determined.

Magnetic resonance imaging of skewfoot.

Magnetic resonance imaging was used to visualize the ossified and unossified portions of the bones and soft tissues of the feet in order to evaluate the tarsometatarsal anatomy in sixteen children, three months to six years old (mean, fifteen months old), who were seen in the orthopaedic clinic with a suspected diagnosis of skewfoot. Twenty-seven feet were clinically abnormal and five were normal. Of the abnormal feet, twenty-six had a radiographic diagnosis of skewfoot and one, of simple metatarsus adductus. Of the skewfeet, seven had a talocalcaneal angle of 45 degrees or more as measured on the lateral radiograph and six had a talocalcaneal angle of 45 degrees or more as measured on the anterior radiograph. Valgus deformity of the hindfoot was not apparent on clinical examination in any of the children. The talocalcaneal angles measured on the magnetic resonance images corresponded poorly with those measured on the radiographs, possibly because it is not possible to simulate weight-bearing during magnetic resonance imaging or because the effect of partial volume averaging on thin sections. However, magnetic resonance imaging demonstrated the shapes of the bones and the positions of the unossified portions of the bones. Magnetic resonance imaging showed lateral subluxation of the navicular in twenty-four skewfeet, plantar subluxation in ten, and medial subluxation of the first metatarsal on the medial cuneiform in twenty-five. The alignment of the lateral margin of the calcaneus and cuboid on the magnetic resonance images was normal in all patients. Magnetic resonance imaging has the unique ability to show the cartilaginous and ossified portions of the developing bones of the foot.